Conveyance of goods through furnaces and the like



May 16, 1933.

A. sMALLwooD ET AL CONVEYANCE OF GOODS THROUGH FURNACES AND THE LIKE Ilum Filed Dec. 24, 1930 8 Sheets-Sheet l May 16, 1933. A. sMALLwOOD ETAI. 1,909,906

CONVEYANCE OF GOODS THROUGH FURNACES AND THE LIKE Filed Dec. 24, 1930 8Sheets-Sheet 2 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I In n IuII. hIIIIIIIIIIIIII. H H HMH IWIIIII IIIVIIH H H IIIVNIIH II. HHIIII. /W ,I I I I II I III.I.FIII..III II IM If, IATMII. IdmIIIm.,

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A. SMALLWOOD ET AL CONVEYANCE OF GOODS THROUGH FURNACES AND THE LIKE esheets-sheet 3 Filed Dec. 24, 1930 May 16, 1933- A. sMALLwooD ET A1.

CONVEYANCE OF GOODS THROUGH FURNCES AND THE4 LIKE 8 Sheets-Sheet 4 l. Il I I I t I Il. QW u l llll l HUHIH- 999A HNA www l 9% n@ A s x. w A .AUVUUUUQ WHINNHI x. .,.ll Illlmmmldlldn HHHH.. n u L. 11. m N A.. A .m pA A. A A TA l/A A f A HHIHUNMHILHH Sx w May 16, 1933- A. sMALLwooD ETA1.

- coNvEYANcE oF GooDs THROUGH FURNACES AND THE LIKE Filed Deo. 24, 19308 Sheets-Sheet 5 16, 41933. A. SMALLWOOD Er AL CONVEYANCE OF GOODSTHROUGH FURNACES AND THE LIKE Filed Dec. l24., 1930 8 Sheets-Sheet 6 May16, 1933. A. sMALLwooD ET A1.

CONVEYANCE OF' GOODS THROUGH FURNACES AND THE LIKE Filed DSC. 24, 1930 8Sheets-Shee't 7 May 16, 1933.` A. sMALLwoOD ET A1.

CONVEYANCE OF GOODS THROUGH FURNAGES AND THE LIKE Filed Deo. 24, 1950 8Sheets-Sheet 8 Patented May 16, 1933 ALFRED Y sMALLWooD AND JOHN l iENGLAND PATENT OFFICEV rALLoN,A or sME'rHwIcK, NEAR BIRMINGHAM,

. ooNvEYANcE orf GooDs rrrnoUGrrrUnNAcEs AND THE LIKEy Application filedDecember 24, 1930, SierialgNo.

.This inventionl has reference to certain improvements' in connectionwith the conveyance ofr goods through furnaces and the like.4 j l In thevarious methods hithertoapplied for this purpose, including the use ofendless conveyors which carry the work, rotary discs which form a seriesof live rollers, and also what is known as the reciprocating bar orSvalkiiig beam by which the goods progress step by step through thefurnace but remain stationary during the return stroke of the bars,various inconveniences and disadvantages have been experienced. Theendless conveyor method for instance has necessitated the heating of theconveyor parts in addition te the goods treated; the roller disc methodhas necessitated high` poweigand also boxes or carrier sheets for thegoods; whilst the Walking beam arrangement involves the use ofstationary members' for supporting the load during the return stroke ofthe reciprocating bars and has therefore necessitated consta-nt pickingup and putting down of the load.. L The present invention is designedtoi avoid these and other inconveniences and disadf vantages, and toprovide an improved methlod and means of conveyance which shallbeparticularly reliable and efficient and which shall therefore tend Ytoa higherdegree of efficiency in the operation of the furnace or thelike. Y v The invention consists in a method means of conveying goods ona reciprocating bar conveyor, characterized in that the bars are aranged in alternated series which are each adapted for movement bothat'normal level and at a lower level, and further charicterized in thateach series vof lbars is lifted to and lowered from its load-carryingklevel only when movingat thesame synchronized forward speed as thealternated series fof bars5 whereby the loadvis transported uniformlyand uninterruptedly bythe conveyor without anyL relative or4differential movenient between therlaady and theV carrier bars in thedirection of load traverse,l f 'A further feature of the inventionisfthat the alternated series of carrier-bars:4v areV 504,562, and iii,Great Britain OctoberA 8;, 1930.

mounted uponfseparate supports the rising and falling movements ofwhichv are controlled by timing mechanismy geared to the mechanism whichreciprocatesthe bars, these Y supports preferablyiconsisting ofcrossgirders disposed in ybalanced pairs fon rocker arms which arevconnected inseries to the timing mechanism.v f Y In order that theinvention may be clearly 'n understood and readil carried into practice,reference may be haof7 to they accompanying explanatory sheets ofdrawings, in which Figures l, la, and l?) together constitute a sideelevation of the invention as applied by way of yexample to'a'furnaceemployed for 65 continuous heating or heat treatment llof metal sheets,Abars, axles, and the like, the view Ibeing partly iny section vand beingbrought within reduced longitudinal limits .A K by the omission of 'ncertain intermediate 70 parts.

Figure 2' isa plan of Figure 1.

Figure 3 is asectional end elevation `of the furnace, the sectionbeing'tak'en on a plane indicated by the line III- III of-Figure la.k

l Figure 4 is a perspective view showing details Vof the rocker andbalanced girder mechanism for elevating and depressing the twoalternated series-of lreciprocating bars constituting the moving'hearthof the fur- 80 nace, the view being in section likewise taken on a planeindicated by the line III-III of Figure la, with parts of thel furnacesetting omitted for facility of' illustration. Y

Figure 5 is a partly sectional side elevationof themechanism forcontrolling the reciprocation of the two alternated series of bars andfor controlling and timing their balanced rising and falling movements.

Figure v6 is a plan ofthe mechanism shown'inFigure 55 but with thecasing cover removed. Y Y Y i Y In one method ofcarrying the inventioninto effect, as applied in connection with a furnace of the kindillustrated and hereinbefore referred to, the hearth fof the furl naceis constituted overthe whole-or thegreater p'artof its width bylongitudinallyr reciprocating bars arranged sideby side in 10Q twoalternated series 1 and 2 extending throughout the preheating chamber3., the main heating chamber 4, the cooling chamber 5, and the loadingand unloading ext-ensions 6 and 7 at opposite ends, the one series ofbars being movable in a forward direction whilst the other series ofintermediately alternated hars are completing the return stroke at aslightly lower level. The mechanism is so arranged that whilst the metalsheets or goods are making forward progress on the one alternated seriesof bars at thc higher' level, the intermediately alternated barscomplete their backward stroke and also reverse and assume a forwardvelocity equal to that of the hars which for the time being arecarrying' the load, and after assuming such equal velocity theseintermediate bars rise and take the load from the first-mentioned seriesof bars, which are then approaching the end of their forward stroke inreadiness for the same return cycle at the lower level as theintermediate bars which have just assumed the carrying of the load andwhich contin ue to move forward at the higher level until they in turnreach the end of their stroke. By this means the goods under treatmentmove constantly, uniformly, and uninterruptedly through the entirelength of the furnace and its associated cooling chamber. The speed ofmovement-of the bars 1 and 2 in a load-carrying direction need neverexceed the normal rate of travel of the goods through the furnace,

whereas in the case of the intermittent walking beam type of conveyor ithas been necessary for the bars to assume a speed greatly in excess ofthe average speed of the goods through the furnace.

The alternated series of reciprocating bars 1 and 2 are furnished, onthe parts located within the heating chamber 4 and preheating` chamber3, with interlocking refractory heat-resisting blocks 8 havingdovetailed attachments to the bars, lor the bars may be providedalternatively with heat-resisting metallic facings. By means of theseblocks a refractory high-temperature hearth is provided which allows forthe propulsion of either heavy or light loads, whichprovides aninsulated bed and avoids abrasion or damage to the materials conveyed,and which at the same time eliminates heating of the mechanism as theload is heated, thus giving much higher efficiency and ensuringeffective protection for the goods under treatment. The arrangementmoreover is such that subject to very slight clearance the barsfacilitate the provision of virtually a solid hearth.

The mechanism employed for reciproca-ting the two alternated series ofbars 1 and 2 is connected by a timing to the mechanism which elevatesand depreses one or other series of the hars at such times as the twoseries of bars are synchronous in their forward velocity, either shortlyafter the beginning or shortly before the end of the forward stroke. Forthis purpose the drive is taken from a variable-speed motor 9, through aspeed-reducing gear 1() and a reciprocating gear box 11, from which thedrive is transferred to the respective series of bars 1 and 2 by meansof a cam roller V12 mounted on the main shaft and having a cam groove 13into which a pair of ballbearing rollers 14 and 15 are engageable ondiametrically opposite sides'of the cam roller, these rollers 14 and 15being carried by an opposite pair of crossheads 16 and 17 having linkconnections 18 and 19 to a pair of cross girders 20 and 21 to which theforward ends of the two series of bars 1 and 2 are respectivelyattached, the form of the cam groove 13 determining the stroke of thebars and being such that the driving cam roller 12 imparts a preciseforward movement at absolutely uniform speed when the bars are inload-carrying position, with a necessarily faster return movement, andas the same cam groove 13 controls both series of bars, it follows thatthere can be no variation in speed as between the two series of bars 1and 2.

The two alternated series of carrier bars 1 and 2 are supported atsuitable spacings on heavy cross girders 22 and 23 arranged in pairs,each girder supporting alternate lines of bars. These girders 22 and 23are slidably supported by means of small rail tracks 24 upon adjustableball-bearing wheels 25 mounted on the opposite ends of rocker arms 26arranged in pairs on opposite sides of the furnace, by which means eachpair of girders 22 and 23 is automatically self-balancing. The pairs ofrocker arms 26 are interconnected in series by means of levers 27 andlinks 28, 29, and 30 having intermediate double-armed connecting levers31, the link 28 being jointed at 32 to an oscillating frame 33 themovement of which is controlled hy a cam 34 mounted on a countershaft 35which is driven by bevelled gear 36 from the shaft 37 carrying the maindriving` cam roller 12. j

It will be seen that by thus arranging the reciprocating mechanism intiming association with the balancing mechanism, it follows that if thetiming gear is brought into operation only at the critical points in theY strokes of the bars, where both series of bars are moving forward atuniform and absolutely synchronized speed, the movement' of the rockerarm 26 by the timing gear automatically transfers the load from Voneseriesof bars to the intermediately alternated series of hars inprecisely the same way as if there were no reciprocatingV motionY at alland the bars were merely alternately up and down with a maximum therecan be no differential action, friction,

or abrasionas between the load and therespective carrier bars, astransference ofthe load can only and does only take placeat Asuchtimesas the 'whole of the bars are moving forward at the critical andconstant speed of the load,`these conditions beiiigfdue to absoluteinterlocking of the reciprocating mechanism with the timing orliftinglmechanism. Y Y

Y The `reciprocating and timing mechanism is also so disposed as topermit of reversal ofl the direction of tra-vel of the vgoods throughthe furnace, this arrangement being of4 particular service kin theapplication of the invention to ai single-ended chamber, where theloadrequires .to be admitted. in one direction and, after necessarytreatment, to bel discharged from the chamber in the oppositedirection.. Moreover the bars instead ofbeing straight maybefappropriately curved so that the system may be adapted for theconveyance of goods through circular chambers. c c

The furnace hereinbefore described has the following Yimportantadvantages i (a) The metalgsheets or goodsare heated without theintroduction of dead load (hitherto usually of higlily'expensiveheat-resisting metal), this arrangement with proper combustionconditions, giving the maximum thermal efliciency attainable. l

(Z9) `VAll mechanism is eliminated from the heat Zone, so that ordinarymeans of lubrication are'practicable without water-cooling or othermeans which extract heat from thc furnace proper.; Y i y s v(c) TheYtransference of the goods i effected. in such a manner-as to reliminatethe possibility -of scratching vor` surface marking, thereby avoidingthe use of carrier sheets, carrier bars, or trays. j Y V n (d) The meansof transportation oi conveyaiice is of such a character as t-o enablesheets or other goods of eitherthe lightest ror the heaviest-gauge to behandled with equal facilityfand eiiiciency.

(c) `There isno restriction in the length of theA goods to beliandled,and where a wide yhearth area is. used thev saine'is adapted to`accommodate for Y instance two narrow sheets, thus utilizing the wholeof the hearth area- Y (f) The conveying mechanism is of such a formthat, when sheets are being handled, the maximum degree of flatness isensured even in the case of light gauges, so that no y sagging orconsequent buckling of the sheets Call OCCHI'.

(g) The speed of conveyance is readily K adjustable tosuit .therequirements andA characteristics of the load.

(It) By reason of the form anddisposition of the conveying mechanism,thelabor and cost of maintenance is reduced to a minimum, being due onlyto ordinary mechanicalV wear of-the bearings operating under coolconditions.

' The through put capacity of the fur-"i nace isvery substantiallyincreased without any'corresponding increase either in fuel consumptionor in the effective hearth area.

It will be understood that the constructional features of the conveyormay be appropriately varied,l particularly as regards the balancingorinounting of the reciprocating Vbars and the ltiming of theirmovements, without departing from the scope of l. Ak conveyor of.the'reciprocating bai"VV type, comprising alternated series of carrierbars each adapted for movement'atnormal level and at a lower level,vincombination withmechanism whereby each series ofl bars is liftedinto andlowered from its load-carrying level only when movingv at'the'samesynchronized forward speed as .the other alternated series of bars,-thusenabling the load'to vbe transported uniformly` and uninterruptedly bythe conveyor without 'any' relative or differential movement betweenvthe load andthe carrier bars in lthe direction of load traverse.

2. A 'conveyor ofthe reciprocating-bar type, comprising two alternatedseries of 5 carrier bars, mechanism for vcontrolling the reciprocationof saidrbars, balanced pairs of 'Across girders supporting therespective series ofbars so as to adapty eachseries for niove-V` ment atnormal .level and ata lowerv level, and timing mechanism geared directto said reciprocation-controlling mechanismv so as tov control thelifting and loweringmovement-s of s aidgirders, whereby eachfseries vofcarrier bars is lifted into and lowered from its load-carrying ,levelfonly when moving at the same synchronized forward speedas the otheralternated series of bars, thus enabling the load to be transported`uniformly anduniiiterruptedly by the conveyor without any relative ordifferential movement between the load and the carrier bars in the-direction of Vload traverse.

Y 3. A conveyor lofjthe reciprocating lbai' type, comprising twoalternated series of care rier bars, cross girders supporting v,therespective series of bars, rocker, arms supporting saidgirdersinbalanced pairs so asto adapt each series ofbars for movementatwnornial level and aty a'llowe-r level, a-f" driving cam roller, axcamgroove in said V45. tion of load traverse.

i the said carrier bars, to thereby provide an in alternatingrelationship to the other mi gitudinal movement to the startingposition,

: same longitudinal speed as the other strucroller, mechanism actuatedfrom the same cam groove for separately reciprocating the two series ofbars without any relative variation in speed, and timing cam mechanismgeared to said driving cam 'roller so as to actuate said rocker arms forcontrol of the lifting and lowering movements of said balanced girders,whereby each series of carrier bars is lifted into and lowered from itsloadcarrying level only when moving at the same synchronized forwardspeed as the other alternated series of bars, thus enabling the load tobe transported. uniformly and uninterruptcdly by the conveyor withoutany relative or differential movement between the load and the carrierbars in the direction of load traverse.

4:. A furnace or the like of the continuous conveyor type, comprisingcarrier bars arranged. in alternated series extending throughout theentire length both of the furnace and of any extensions thereof so as toconstitute a continuous hearth, in combination with mechanism forseparately reciprocating said alternated series of bars, cross girderssupporting the respective' series of bars, rocker arms supporting saidgirders in bala-need pairs so as to adapt each series of bars formovement at normal hearth level and at a lower level, and timingmechanism geared to said reciprocationcontrolling mechanism so as toactuate said rocker arms for control of the lifting and loweringmovements of said balanced girders, whereby each series of reciprocatingcarrier bars is lifted to and lowered from its load-carrying hearthlevel only when moving at the same synchronized forward speed as theother series of bars, thus enabling the load to be transported uniformlyand uninterruptedly from one end to the other of the hearth without anyrelative or differential movement between the load and the respectiveseries of carrier bars in the direc- 5. A furnace or the like of thecontinuous conveyor type in accordance with claim 1, includinginterlocking facing blocks of refra-ctoryheat-resisting materialattached to insulated high-temperature moving hearth.

6. A conveyor mechanism comprising a pair of cooperating load carryingstructures, and means for imparting to each structure structure upwardmovement to a predetermined level, longitudinal movement in onedirection at"y said level, subsequent downward movement, and thereafterreturn lonsaid means being effective to raise each of the structures tothe predetermined level prior to lowering of the other structure, toimpart to the structure being raised the ture by the time the structurebeing raised has reached the level of the other structure, and to moveboth structures longitudinally in the same direction and at the samerate'of speed during the time that the structures are disposed at thepredetermined upper level.

7. A conveyor mechanism comprising a pair of cooperating load carryingstructures, means for alternately raising said structures to a commonlevel and lowering them below said level, and means for impartingVlongitudinal movement to each structure in one direction when it is atits upper level and for imparting return longitudinal movement theretowhen itis at a lower level, said first mentioned means being effectiveto raise each supporting structure to the upper level prior to loweringof the other supporting structure to the lower level., and said secondmentioned means being eective to impart to each supporting structure asit is raised the same longitudinal speed as the other structure by thetime the structure being raised has reached the level of the otherstructure and to move both supporting structures longitudinally in thesame direction and at the same rate of speed when both of saidstructures are disposed at the upper level.

8. A conveyor mechanism as set forth in claim 6 in which the means forimparting longitudinal movement in both directions to both of the loadcarrying structures comprises a single cam. l

9. The method ofv operating a conveyor mechanism of the type comprisingseparate load carrying structures, which consists in alternately raisingand lowering said structures to cause them to alternately support theload, imparting longitudinal load advancing movement to each structurewhen the same is in a raised position, imparting return longitudinalmovement to each structure when the samey is in its lowered-position,bringing each load carrying structure during its raising movement up tothe same longitudinal speed as the other load carryin structure, andmoving both structures longitudinally at the same load advancing speedwhen said structures are in their upper or load transfer andtransporting posi-

